This is a competitive renewal of NIH T32 DK-07519 entitled: Regulation of Hematopoietic Cell Production which is currently in its 30th year of funding. The discipline of stem cells and hematopoiesis has led to numerous discoveries that have enhanced our understanding of blood cells and the treatment of non-malignant and malignant disorders. However, to advance the field, we must train the next generation of investigators in this area. The aim of this program is to continue to train this next generation of scientists in the clinically-relevant medical area of stem cells and hematopoiesis for effective modulation of normal and abnormal cell growth and to correct blood diseases. We request 4 pre- and 5 post-doctoral slots, for this competitive renewal. We have an outstanding group of 26 very productive, interactive, and well-respected investigators as mentors with their primary and/or secondary faculty appointments in 8 departments of the medical school. These mentors have over their career trained 190 pre- doctoral and 361 MD/PhD post-doctoral students. Since 2005, we were able to train and/or are in the process of training 15 pre- and 22 post-doctoral students, who have published 158 papers [72 (Pre-Doc) and 86 (Post-Doc)]. Our preceptors have published 2689 refereed papers of which 48.9% were co-published with their students. Since 2010, they have published 691 refereed papers, of which 58.9% were with their students. The Program Director (PD) has trained 16 pre-doctoral and 58 post-doctoral/clinical fellows, has published over 740 papers and been continuously funded by the NIH since 1978. He is a recognized authority on hematopoietic stem and progenitor cells, the regulation of hematopoiesis, and has had his work translated into clinical utility. The Co-PD, is also a well- recognized and well-funded productive investigator who has trained numerous students and fellows, and has had his work translated for clinical benefit. The PD and Co-PD have extensive administrative experience and have worked for many years in the area of stem cell biology and hematopoiesis in efforts to enhance treatment for hematological disorders. The vast majority of our trainees, since initial funding of this grant in 1985, have gone on to careers in academia and other research intensive areas of employment. Training of our pre- and post-doctoral students entails one-on-one interactions, committee and group mentorship, lab meetings, special seminars in the area of this training program, didactic courses, ethical training, presentations at scientific meetings and high expectations for the trainees to publish in respected scientific and medical journals, and to continue in their career development leading them to become productive independent investigators whose work will benefit healthcare in general and hematopoietic and stem cell therapy in specific. Our training efforts are monitored and enhanced by both internal and external advisory committees.